1 / 6

HBD status for Run9

HBD status for Run9. Takao for HBD group. Detector/Readout/HV status. Both West and East have been installed yesterday As of Run6, HBD readout has been working fine. We take 12 FACD samples per trigger Post and pre charge are computed from means of three samples each

mcorcoran
Download Presentation

HBD status for Run9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HBD status for Run9 Takao for HBD group kick-off Run9 DAQ meeting

  2. Detector/Readout/HV status • Both West and East have been installed yesterday • As of Run6, HBD readout has been working fine. • We take 12 FACD samples per trigger • Post and pre charge are computed from means of three samples each • Data volume from DCM: 1919(ch) *12/2(we pack 2 channels into one word) = 11Kword = 46kB (at maximum) • We have 12 fibers: 4kB/fiber • Zero-suppression will reduce the size • HV server/client program are re-designed to accommodate new hardware-based trip reduction scheme kick-off Run9 DAQ meeting

  3. Run policies • We run at +/- field only for physics • How about ++ field? • How long we can continue to take data as a single run • As long as no trip occurred? • Threshold of requesting stop of the run • More than a half of HV modules are tripped? • We will need to measure our pedestal values to prepare the zero suppression. This does not require beam and might be repeated on an infrequent basis (every few weeks) • Need sizeable sample (10-40 million events) for early gain calibration using “All triggers” to see scintillation. • We need to have minimum bias events to show alive channel count. • We would like to also have reconstruction of electron tracks in ERT-electron triggers online as a set of data used to evaluate detector performance online. This should make specialized micro-DST files for subsequent analysis with many passes as we learn what we’re doing. • These files can be HIGHLY filtered to only keep the very best events for subsequent efficient analysis with minimal disk space usage. • We need a single zero field run in the early days with ERT-electron trigger for alignment. kick-off Run9 DAQ meeting

  4. Backup kick-off Run9 DAQ meeting

  5. HBD Readout size for Run-8? A case: 20:00, June 24, 2007 Takao Sakaguchi • Data: Run 240065, segment 85 • I took it because this run is still left in 1008 disk • Only 7 fibers (East) out of 12 were read out • One out of the seven looks to have taken care of a module with HV off • 1 of 7 did not have its HV on • Each fiber supposedly took care of one detector module • Total event size: 226KB/evt • HBD event size: 6.6KB/evt • Threshold were 3 sigma for valid modules • HV set to of each modules: 3550-3750V, drift field: -30V kick-off Run9 DAQ meeting

  6. Extrapolating to full module operation • Size significantly reduced after Chi’s “packing two samples into one” • factor of two reduction in size • No more “packing” seems to be possible • Requirement was to reduce data volume per fiber “before going to SEB” • Flow: FEM-> DCM-> SEB(Sub Event Buffer)-> EVB(Event builder)-> Disk • The big volume is still OK as long as volume per fiber is within a tolerance • Event size per fiber is the one that determines how many event we can take per second. • Also, reducing data volume before DCM is not necessarily required • That’s why raising zero-suppression threshold did help. It just reduced the size of data going out from DCM • Right now, we are taking 12 samples per channel per event. • Since we calculate signal by “samp(0+1+2)-samp(8+9+10)”, we could drop rest six samples • It reduces the size by a factor of two. Of course, need reexamination of the samples to take • Then, full operation would give: 6.6[KB/evt](24/6)(1/2) = 13[KB/evt] • The limit we could go kick-off Run9 DAQ meeting

More Related